fbvnc.c

   1 /*
   2  * fbvnc - a small linux framebuffer vnc viewer
   3  *
   4  * Copyright (C) 2009-2013 Ali Gholami Rudi
   5  *
   6  * This program is released under the modified BSD license.
   7  */
   8 #include <arpa/inet.h>
   9 #include <ctype.h>
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <netdb.h>
  13 #include <netinet/in.h>
  14 #include <poll.h>
  15 #include <pwd.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <termios.h>
  20 #include <unistd.h>
  21 #include <sys/socket.h>
  22 #include <sys/stat.h>
  23 #include <sys/types.h>
  24 #include <linux/input.h>
  25 #include "draw.h"
  26 #include "vnc.h"
  27
  28 #define MIN(a, b)       ((a) < (b) ? (a) : (b))
  29 #define MAX(a, b)       ((a) > (b) ? (a) : (b))
  30 #define OUT(msg)        write(1, (msg), strlen(msg))
  31
  32 #define VNC_PORT        "5900"
  33 #define SCRSCRL         2
  34 #define MAXRES          (1 << 16)
  35
  36 static int cols, rows;          /* framebuffer dimensions */
  37 static int bpp;                 /* bytes per pixel */
  38 static int srv_cols, srv_rows;  /* server screen dimensions */
  39 static int or, oc;              /* visible screen offset */
  40 static int mr, mc;              /* mouse position */
  41 static int nodraw;              /* don't draw anything */
  42
  43 static char buf[MAXRES];
  44
  45 static int vnc_connect(char *addr, char *port)
  46 {
  47         struct addrinfo hints, *addrinfo;
  48         int fd;
  49
  50         memset(&hints, 0, sizeof(hints));
  51         hints.ai_family = AF_UNSPEC;
  52         hints.ai_socktype = SOCK_STREAM;
  53         hints.ai_flags = AI_PASSIVE;
  54
  55         if (getaddrinfo(addr, port, &hints, &addrinfo))
  56                 return -1;
  57         fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
  58                         addrinfo->ai_protocol);
  59
  60         if (connect(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) == -1) {
  61                 close(fd);
  62                 freeaddrinfo(addrinfo);
  63                 return -1;
  64         }
  65         freeaddrinfo(addrinfo);
  66         return fd;
  67 }
  68
  69 static void fbmode_bits(int *rr, int *rg, int *rb)
  70 {
  71         int mode = FBM_COLORS(fb_mode());
  72         *rr = (mode >> 8) & 0xf;
  73         *rg = (mode >> 4) & 0xf;
  74         *rb = (mode >> 0) & 0xf;
  75 }
  76
  77 static int vnc_init(int fd)
  78 {
  79         char vncver[] = "RFB 003.003\n";
  80         int rr, rg, rb;
  81
  82         struct vnc_client_init clientinit;
  83         struct vnc_server_init serverinit;
  84         struct vnc_client_pixelfmt pixfmt_cmd;
  85         int connstat = VNC_CONN_FAILED;
  86
  87         write(fd, vncver, 12);
  88         read(fd, vncver, 12);
  89
  90         read(fd, &connstat, sizeof(connstat));
  91
  92         if (ntohl(connstat) != VNC_CONN_NOAUTH)
  93                 return -1;
  94
  95         clientinit.shared = 1;
  96         write(fd, &clientinit, sizeof(clientinit));
  97         read(fd, &serverinit, sizeof(serverinit));
  98
  99         if (fb_init())
 100                 return -1;
 101         srv_cols = ntohs(serverinit.w);
 102         srv_rows = ntohs(serverinit.h);
 103         cols = MIN(srv_cols, fb_cols());
 104         rows = MIN(srv_rows, fb_rows());
 105         bpp = FBM_BPP(fb_mode());
 106         mr = rows / 2;
 107         mc = cols / 2;
 108
 109         read(fd, buf, ntohl(serverinit.len));
 110         pixfmt_cmd.type = VNC_CLIENT_PIXFMT;
 111         pixfmt_cmd.format.bpp = bpp << 3;
 112         pixfmt_cmd.format.depth = bpp << 3;
 113         pixfmt_cmd.format.bigendian = 0;
 114         pixfmt_cmd.format.truecolor = 1;
 115
 116         fbmode_bits(&rr, &rg, &rb);
 117         pixfmt_cmd.format.rmax = htons((1 << rr) - 1);
 118         pixfmt_cmd.format.gmax = htons((1 << rg) - 1);
 119         pixfmt_cmd.format.bmax = htons((1 << rb) - 1);
 120         /* assuming colors packed as RGB; shall handle other cases later */
 121         pixfmt_cmd.format.rshl = rg + rb;
 122         pixfmt_cmd.format.gshl = rb;
 123         pixfmt_cmd.format.bshl = 0;
 124         write(fd, &pixfmt_cmd, sizeof(pixfmt_cmd));
 125         return 0;
 126 }
 127
 128 static int vnc_free(void)
 129 {
 130         fb_free();
 131         return 0;
 132 }
 133
 134 static int vnc_refresh(int fd, int inc)
 135 {
 136         struct vnc_client_fbup fbup_req;
 137         fbup_req.type = VNC_CLIENT_FBUP;
 138         fbup_req.inc = inc;
 139         fbup_req.x = htons(oc);
 140         fbup_req.y = htons(or);
 141         fbup_req.w = htons(cols);
 142         fbup_req.h = htons(rows);
 143         return write(fd, &fbup_req, sizeof(fbup_req)) != sizeof(fbup_req);
 144 }
 145
 146 static void drawfb(char *s, int x, int y, int w, int h)
 147 {
 148         int sc;         /* screen column offset */
 149         int bc, bw;     /* buffer column offset / row width */
 150         int i;
 151         sc = MAX(0, x - oc);
 152         bc = x > oc ? 0 : oc - x;
 153         bw = x + w < oc + cols ? w - bc : w - bc - (x + w - oc - cols);
 154         for (i = y; i < y + h; i++)
 155                 if (i - or >= 0 && i - or < rows && bw > 0)
 156                         fb_set(i - or, sc, s + ((i - y) * w + bc) * bpp, bw);
 157 }
 158
 159 static void xread(int fd, void *buf, int len)
 160 {
 161         int nr = 0;
 162         int n;
 163         while (nr < len && (n = read(fd, buf + nr, len - nr)) > 0)
 164                 nr += n;
 165         if (nr < len) {
 166                 printf("partial vnc read!\n");
 167                 exit(1);
 168         }
 169 }
 170
 171 static int vnc_event(int fd)
 172 {
 173         struct vnc_rect uprect;
 174         char msg[1 << 12];
 175         struct vnc_server_fbup *fbup = (void *) msg;
 176         struct vnc_server_cuttext *cuttext = (void *) msg;
 177         struct vnc_server_colormap *colormap = (void *) msg;
 178         int i, j;
 179         int n;
 180
 181         if (read(fd, msg, 1) != 1)
 182                 return -1;
 183         switch (msg[0]) {
 184         case VNC_SERVER_FBUP:
 185                 xread(fd, msg + 1, sizeof(*fbup) - 1);
 186                 n = ntohs(fbup->n);
 187                 for (j = 0; j < n; j++) {
 188                         int x, y, w, h;
 189                         xread(fd, &uprect, sizeof(uprect));
 190                         x = ntohs(uprect.x);
 191                         y = ntohs(uprect.y);
 192                         w = ntohs(uprect.w);
 193                         h = ntohs(uprect.h);
 194                         if (x >= srv_cols || x + w > srv_cols)
 195                                 return -1;
 196                         if (y >= srv_rows || y + h > srv_rows)
 197                                 return -1;
 198                         for (i = 0; i < h; i++) {
 199                                 xread(fd, buf, w * bpp);
 200                                 if (!nodraw)
 201                                         drawfb(buf, x, y + i, w, 1);
 202                         }
 203                 }
 204                 break;
 205         case VNC_SERVER_BELL:
 206                 break;
 207         case VNC_SERVER_CUTTEXT:
 208                 xread(fd, msg + 1, sizeof(*cuttext) - 1);
 209                 xread(fd, buf, ntohl(cuttext->len));
 210                 break;
 211         case VNC_SERVER_COLORMAP:
 212                 xread(fd, msg + 1, sizeof(*colormap) - 1);
 213                 xread(fd, buf, ntohs(colormap->n) * 3 * 2);
 214                 break;
 215         default:
 216                 fprintf(stderr, "unknown vnc msg: %d\n", msg[0]);
 217                 return -1;
 218         }
 219         return 0;
 220 }
 221
 222 static int rat_event(int fd, int ratfd)
 223 {
 224         char ie[4];
 225         struct vnc_client_ratevent me = {VNC_CLIENT_RATEVENT};
 226         int mask = 0;
 227         int or_ = or, oc_ = oc;
 228         if (read(ratfd, &ie, sizeof(ie)) != 4)
 229                 return -1;
 230         /* ignore mouse movements when nodraw */
 231         if (nodraw)
 232                 return 0;
 233         mc += ie[1];
 234         mr -= ie[2];
 235
 236         if (mc < oc)
 237                 oc = MAX(0, oc - cols / SCRSCRL);
 238         if (mc >= oc + cols && oc + cols < srv_cols)
 239                 oc = MIN(srv_cols - cols, oc + cols / SCRSCRL);
 240         if (mr < or)
 241                 or = MAX(0, or - rows / SCRSCRL);
 242         if (mr >= or + rows && or + rows < srv_rows)
 243                 or = MIN(srv_rows - rows, or + rows / SCRSCRL);
 244         mc = MAX(oc, MIN(oc + cols - 1, mc));
 245         mr = MAX(or, MIN(or + rows - 1, mr));
 246         if (ie[0] & 0x01)
 247                 mask |= VNC_BUTTON1_MASK;
 248         if (ie[0] & 0x04)
 249                 mask |= VNC_BUTTON2_MASK;
 250         if (ie[0] & 0x02)
 251                 mask |= VNC_BUTTON3_MASK;
 252         if (ie[3] > 0)          /* wheel up */
 253                 mask |= VNC_BUTTON4_MASK;
 254         if (ie[3] < 0)          /* wheel down */
 255                 mask |= VNC_BUTTON5_MASK;
 256
 257         me.y = htons(mr);
 258         me.x = htons(mc);
 259         me.mask = mask;
 260         write(fd, &me, sizeof(me));
 261         if (or != or_ || oc != oc_)
 262                 if (vnc_refresh(fd, 0))
 263                         return -1;
 264         return 0;
 265 }
 266
 267 static int press(int fd, int key, int down)
 268 {
 269         struct vnc_client_keyevent ke = {VNC_CLIENT_KEYEVENT};
 270         ke.key = htonl(key);
 271         ke.down = down;
 272         return write(fd, &ke, sizeof(ke));
 273 }
 274
 275 static void showmsg(void)
 276 {
 277         OUT("\x1b[H\t\t\t*** fbvnc ***\r");
 278 }
 279
 280 static int kbd_event(int fd, int kbdfd)
 281 {
 282         char key[1024];
 283         int i, nr;
 284
 285         if ((nr = read(kbdfd, key, sizeof(key))) <= 0 )
 286                 return -1;
 287         for (i = 0; i < nr; i++) {
 288                 int k = -1;
 289                 int mod[4];
 290                 int nmod = 0;
 291                 switch (key[i]) {
 292                 case 0x08:
 293                 case 0x7f:
 294                         k = 0xff08;
 295                         break;
 296                 case 0x09:
 297                         k = 0xff09;
 298                         break;
 299                 case 0x1b:
 300                         if (i + 2 < nr && key[i + 1] == '[') {
 301                                 if (key[i + 2] == 'A')
 302                                         k = 0xff52;
 303                                 if (key[i + 2] == 'B')
 304                                         k = 0xff54;
 305                                 if (key[i + 2] == 'C')
 306                                         k = 0xff53;
 307                                 if (key[i + 2] == 'D')
 308                                         k = 0xff51;
 309                                 if (key[i + 2] == 'H')
 310                                         k = 0xff50;
 311                                 if (k > 0) {
 312                                         i += 2;
 313                                         break;
 314                                 }
 315                         }
 316                         k = 0xff1b;
 317                         if (i + 1 < nr) {
 318                                 mod[nmod++] = 0xffe9;
 319                                 k = key[++i];
 320                                 if (k == 0x03)  /* esc-^C: quit */
 321                                         return -1;
 322                         }
 323                         break;
 324                 case 0x0d:
 325                         k = 0xff0d;
 326                         break;
 327                 case 0x0:       /* c-space: stop/start drawing */
 328                         if (!nodraw) {
 329                                 nodraw = 1;
 330                                 showmsg();
 331                         } else {
 332                                 nodraw = 0;
 333                                 if (vnc_refresh(fd, 0))
 334                                         return -1;
 335                         }
 336                 default:
 337                         k = (unsigned char) key[i];
 338                 }
 339                 if (k >= 'A' && k <= 'Z' || strchr(":\"<>?{}|+_()*&^%$#@!~", k))
 340                         mod[nmod++] = 0xffe1;
 341                 if (k >= 1 && k <= 26) {
 342                         k = 'a' + k - 1;
 343                         mod[nmod++] = 0xffe3;
 344                 }
 345                 if (k > 0) {
 346                         int j;
 347                         for (j = 0; j < nmod; j++)
 348                                 press(fd, mod[j], 1);
 349                         press(fd, k, 1);
 350                         press(fd, k, 0);
 351                         for (j = 0; j < nmod; j++)
 352                                 press(fd, mod[j], 0);
 353                 }
 354         }
 355         return 0;
 356 }
 357
 358 static void term_setup(struct termios *ti)
 359 {
 360         struct termios termios;
 361         OUT("\033[2J");         /* clear the screen */
 362         OUT("\033[?25l");       /* hide the cursor */
 363         showmsg();
 364         tcgetattr(0, &termios);
 365         *ti = termios;
 366         cfmakeraw(&termios);
 367         tcsetattr(0, TCSANOW, &termios);
 368 }
 369
 370 static void term_cleanup(struct termios *ti)
 371 {
 372         tcsetattr(0, TCSANOW, ti);
 373         OUT("\r\n\033[?25h");   /* show the cursor */
 374 }
 375
 376 static void mainloop(int vnc_fd, int kbd_fd, int rat_fd)
 377 {
 378         struct pollfd ufds[3];
 379         int pending = 0;
 380         int err;
 381         ufds[0].fd = kbd_fd;
 382         ufds[0].events = POLLIN;
 383         ufds[1].fd = vnc_fd;
 384         ufds[1].events = POLLIN;
 385         ufds[2].fd = rat_fd;
 386         ufds[2].events = POLLIN;
 387         if (vnc_refresh(vnc_fd, 0))
 388                 return;
 389         while (1) {
 390                 err = poll(ufds, 3, 500);
 391                 if (err == -1 && errno != EINTR)
 392                         break;
 393                 if (!err)
 394                         continue;
 395                 if (ufds[0].revents & POLLIN)
 396                         if (kbd_event(vnc_fd, kbd_fd) == -1)
 397                                 break;
 398                 if (ufds[1].revents & POLLIN) {
 399                         if (vnc_event(vnc_fd) == -1)
 400                                 break;
 401                         pending = 0;
 402                 }
 403                 if (ufds[2].revents & POLLIN)
 404                         if (rat_event(vnc_fd, rat_fd) == -1)
 405                                 break;
 406                 if (!pending++)
 407                         if (vnc_refresh(vnc_fd, 1))
 408                                 break;
 409         }
 410 }
 411
 412 int main(int argc, char * argv[])
 413 {
 414         char *port = VNC_PORT;
 415         char *host = "127.0.0.1";
 416         struct termios ti;
 417         int vnc_fd, rat_fd;
 418         if (argc >= 2)
 419                 host = argv[1];
 420         if (argc >= 3)
 421                 port = argv[2];
 422         if ((vnc_fd = vnc_connect(host, port)) < 0) {
 423                 fprintf(stderr, "could not connect!\n");
 424                 return 1;
 425         }
 426         if (vnc_init(vnc_fd) < 0) {
 427                 close(vnc_fd);
 428                 fprintf(stderr, "vnc init failed!\n");
 429                 return 1;
 430         }
 431         term_setup(&ti);
 432
 433         /* entering intellimouse for using mouse wheel */
 434         rat_fd = open("/dev/input/mice", O_RDWR);
 435         write(rat_fd, "\xf3\xc8\xf3\x64\xf3\x50", 6);
 436         read(rat_fd, buf, 1);
 437
 438         mainloop(vnc_fd, 0, rat_fd);
 439
 440         term_cleanup(&ti);
 441         vnc_free();
 442         close(vnc_fd);
 443         close(rat_fd);
 444         return 0;
 445 }